So-called Point to Point short messages have been used in the GSM (Global System for Mobile communications). Point to Point short messages are short, max. 160 characters long short messages transmitted and received by a GSM mobile phone. Short messages have also been called text messages according to their most common use. These short messages can also be concatenated for transferring a message more than 160 characters long. Concatenated text messages can be used, in particular, in advanced mobile stations, such as Nokia 9000 Communicator, which have a large display in relation to the mobile station's size, and a QWERTY keyboard.
Initiating a call during the transmission of a short message does not always succeed although the transmission of a short message during a call does. The reason for this may be for example that a GSM network ignores the call request or rejects the request and informs the mobile station, requesting a call, of this. In this case, in order to implement the call, a user must wait until the ongoing transfer of a short message from the GSM phone to be used for making the call, ends. It does not take long to wait for the ending of the transfer of one short message, only a few seconds, but if there are a larger number of short messages to be transferred for transferring the above-mentioned longer messages, the user may have to wait for several minutes before the short messages have been transmitted, and he can again make a call with his phone. In the GSM controlled interruption of the transmission of a short message being transmitted is not allowed.